DOCSLIB.ORG

In Vitro Inhibition of Several Phytopathogenic Fungi from Avocado by Soluble Potassium Silicate T F Bekker1, C Kaiser1 and N Labuschagne2

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
In Vitro Inhibition of Several Phytopathogenic Fungi from Avocado by Soluble Potassium Silicate T F Bekker1, C Kaiser1 and N Labuschagne2 In vitro inhibition of several phytopathogenic fungi from avocado by soluble potassium silicate T F Bekker1, C Kaiser1 and N Labuschagne2 1Department of Plant Production and Soil Science 2Department of Microbiology and Plant Pathology University of Pretoria, Pretoria 0002, South Africa ABSTRACT Silicon is a bioactive element only recently implicated as having fungicidal properties. The present study examined water soluble liquid potassium silicate for activity against several types of avocado phytopathogenic fungi. In vitro dose-responses towards solu- ble potassium silicate (20.7% silicon dioxide) were determined for Phytophthora cinnamomi, Phomopsis perniciosa, Pestalotiopsis maculans, Lasiodiplodia theobromae, Glomerella cingulata, Natrassia sp., and Collectotrichum gloeosporioides. Inhibition of mycelial growth was dose-dependant with 100% inhibition observed at 80 ml (pH 11.7) and 40 ml (pH 11.5) soluble potassium silicate (20.7% silicon dioxide) per litre of agar, for all fungi tested in two of the replicate experiments with the exception of Natrassia sp., G. cingulata and C. gloeosporioides at 40 ml in one replication. For both replicate experiments, Phytophthora cinnamomi, Phomopsis perniciosa, Pestalotiopsis maculans, Lasiodiplodia theobromae, Glomerella cingulata, Natrassia sp., and Collectotrichum gloeosporioides were only partially inhibited at 5, 10 and 20 ml soluble potassium silicate per litre of agar. Percentage inhibition was, however, positively correlated with soluble potassium silicate concentrations. Soluble potassium silicate raised the pH of the agar from 5.6 to between 10.3 and 11.7 at concentrations of 5 and 80 ml soluble potassium silicate per litre of agar respectively. The effect of pH on fungal growth does not follow a clear trend for all fungi tested. In the absence of soluble potassium silicate, high pH caused only partial inhibition of mycelial growth. Soluble potassium silicate therefore suppresses fungal growth effectively in vitro and this is largely a fungicidal effect. INTRODUCTION of soluble potassium silicate against phytopathogenic fungi af- It has long been known that silicon reduces the incidence of fecting avocado. fungal diseases in various pathosystems (Fauteux, Rémus-Borel, Numerous avocado diseases are caused by pathogenic fun- Menzies & Bélanger, 2005). Numerous studies have shown in- gi present in the soil or air within avocado orchards. In many creased resistance to fungal plant diseases as a response to sili- instances the world has become reliant on chemical control of con applications. These include increased resistance to powdery these diseases, with the fear of fungicide resistance ever in- mildew (Uncinula necator) in grapes (Bowen, Menzies & Ehret, creasing (Hardy, Barrett & Shearer, 2001). 1992), powdery mildew (Sphaerotheca fuliginea) in cucumbers Development of fungicide resistant strains of phytopathogenic (Adatia & Besford, 1986; Belanger, Bowen, Ehret, & Menzies, fungi has been amply demonstrated. It is therefore imperative 1995), powdery mildew (Erysiphe cichoracearum) in muskmel- that alternative control measures should be investigated.The ons (Menzies, Bowen & Ehret, 1992) as well as Cladosporium current study was therefore initiated to assess the in vitro effect spp. and Pythium spp. in cucumbers (Chérif, Asselin & Belanger, of soluble potassium silicate on Phytophthora cinnamomi and six 1994). It was proposed that amorphous silica deposition in the other pathogenic fungi affecting avocado. leaf apoplast prevent penetration of fungal hyphae (Carver, Zey- en & Ahlstrand, 1987; Kunoh & Ishizaki, 1975). Although this in MATERIALS AND METHODS part explains the prophylactic properties of silicon, monomeric Fungi tested silicon is also implicated in activation of several plant natural Isolates of seven fungal pathogens of avocado maintained on defences (Fauteux et al., 2005), such as fl avanoids phytoalexin potato dextrose agar (PDA) were obtained from the Mycological mediated response to silicon applications (Fawe, Abou-Zaid, herbarium of the Plant Protection Research Institute, Agricultural Menzies & Belanger, 1988) and prophylactic properties of silicon Research Council (ARC), Pretoria, and Westfalia Technological in plant defence reactions to fungal attack (Chérif et al., 1994). Table 1. Fungal pathogens of avocado tested for their in vitro sensitivity to soluble potassium Bekker, Kaiser, Van der silicate (20.7% silicon dioxide). Merwe & Labuschagne (2006) demonstrated for the fi rst time that soluble potassium silicate has di- rect in vitro fungitoxic ac- tivity against a wide range of fungi. In the current study we are investigat- ing the fungitoxic activity 64 SOUTH AFRICAN AVOCADO GROWERS’ ASSOCIATION YEARBOOK 29, 2006 Services (WTS), Tzaneen, South Africa. Fungi were selected on silicate added) served as a control. the basis of availability of cultures as well as their importance as A 5 mm diam. mycelial disc taken from a 7 d old fungal culture avocado pathogens (Table 1). on PDA was transferred to the centre of a Petri dish containing soluble potassium silicate amended PDA at the various concen- Agar preparation trations, as well as unamended (control) plates respectively. Soluble potassium silicate solution was sterilized by passing This was done for each fungus. Ten replicates were included through a 0.45 μm Millipore fi lter before adding it to autoclaved for each treatment, with the entire experiment replicated twice. potato dextrose agar (PDA) to give fi nal concentrations of 5, 10, Plates were incubated at 25˚C in the dark and colony diameters 20, 40 and 80 ml soluble potassium silicate (20.7% silicon diox- were measured every second day for 8 consecutive days. ide) per litre of PDA. Soluble potassium silicate (20.7% silicon dioxide) has a pH of Percentage inhibition was calculated according to the formula: 12.7, which markedly increase the pH of PDA. A pilot study was thus conducted to determine the effect of various concentrations Percentage inhibition = (C-T) x 100 of soluble potassium silicate on the pH of PDA. It was found that C unameliorated PDA has a pH of 5.6. Upon addition of 5, 10, 20, Where C = colony diameter (mm) of the control 40 and 80 ml of soluble potassium silicate, the pH of the PDA is T = colony diameter (mm) of the test plate raised to 10.3, 10.7, 11.2, 11.5 and 11.7 respectively. This data was analysed with Genstat 4.23 DE (Table 2, 3 and The pH of PDA plates in the current study were therefore ad- 4). justed to pH 10.3, 10.7, 11.2, 11.5 and 11.7 using soluble potas- sium hydroxide. A non-ameliorated PDA (i.e. with no potassium RESULTS Soluble potassium silicate (20.7% silicon dioxide) completely Table 2. Mycelial growth of Phytophthora cinnamomi suppressed mycelial growth of all fungi (Table 3) at concentra- incubated for eight days at 25˚C on PDA. Agar was tions of 40 and 80 ml.l-1 PDA, with the exception of Natrassia sp., either amended with soluble potassium silicate G. cingulata and C. gloeosporioides (mean colony diam. of 5.4, (20.7% silicon dioxide) at various concentrations, or 11.5 and 13.1 mm respectively) in one experimental repetition. potassium hydroxide to increase pH value of the agar, A soluble potassium silicate concentration of 5-10 ml.ℓ-1 PDA after amendment with soluble potassium hydroxide inhibited mycelial growth of P. cinnamomi (Figure 1; Table 2), mimicking the pH effect of soluble potassium silicate. but in contrast increased fungal growth of P. perniciosa (Figure 2). Suppression of mycelial growth at concentrations of 5 to 20 ml.ℓ-1 PDA varied between all fungi tested and an effective sup- pressive concentration are to be determined for each fungus. Although PDA amended with soluble potassium hydroxide (pH range 10.3 to 11.7) did inhibit mycelial growth of most fungi to some degree (Table 3), the effect of added soluble potassium silicate over and above the pH effect is apparent. The effect of pH on mycelial growth as exemplifi ed by soluble potassium hy- droxide amended PDA plates seems to be species-specifi c, and is not correlated to the inhibition due to soluble potassium silicate presence. DISCUSSION The results of this study clearly indicate that soluble potassium silicate (20.7% silicon dioxide) has fungicidal activity in vitro. w pH value of the agar after amendment with soluble Seebold (1998) and Seebold, Datnoff, Correa-Victoria & Snyder potassium silicate. (1995) confi rmed this when soluble potassium silicate tested x Means of 10 plates/ treatment. Measurements include as a fungicide resulted in a 40% suppression of rice neck blast. initial 5 mm diam. mycelial disc. Suppression of fungal growth in the current study was shown to y Concentration of the soluble potassium silicate per litre of be dose dependent. However, growth of some fungi such as P. PDA growth medium. perniciosa was actually stimulated at a concentration of 5 ml.ℓ-1 z In each column, values followed by the same letter do not soluble potassium silicate. This phenomenon has been noted in differ signifi cantly (F.Pr < 0.01). numerous fungi with silicon by Wainwright, Al-Wajeeh & Gray- Table 3. Mean % inhibition of different fungi at different soluble potassium silicate (20.7% SiO2) concentrations and different pH values in ameliorated potato dextrose agar. SOUTH AFRICAN AVOCADO GROWERS’ ASSOCIATION YEARBOOK 29, 2006 65 Table 4. Mean colony diameter (minus 5 mm diam. initial disc) of different fungi at different soluble potassium silicate concentrations and different pH values in ameliorated PDA on the day when the fi rst concentration
Load more

Recommended publications
  • Botryosphaeria Infections in New Zealand Grapevine Nurseries: Sources of Inoculum and Infection Pathways
    Lincoln University Digital Thesis Copyright Statement The digital copy of this thesis is protected by the Copyright Act 1994 (New Zealand). This thesis may be consulted by you, provided you comply with the provisions of the Act and the following conditions of use: you will use the copy only for the purposes of research or private study you will recognise the author's right to be identified as the author of the thesis and due acknowledgement will be made to the author where appropriate you will obtain the author's permission before publishing any material from the thesis. Botryosphaeria infections in New Zealand grapevine nurseries: Sources of inoculum and infection pathways A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy in Plant Pathology by Regina Billones-Baaijens Lincoln University 2011 Abstract of a thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy in Plant Pathology Abstract Botryosphaeria infections in New Zealand grapevine nurseries: Inoculum sources and infection pathways by Regina Billones-Baaijens The botryosphaeriaceous fungi can cause decline, dieback and death of grapevines. Anecdotal evidence has indicated that these pathogens might be present in the young vines sold by propagation nurseries, so this study investigated their role in spread of this disease. Sampling of grapevine nurseries across New Zealand showed that botryosphaeriaceous infections were present in eight out of nine nurseries with infection incidence ranging from 5 to 63%. Of the 311 propagation materials and plants received, 23% were positive for botryosphaeriaceous infection, with a total of 120 isolates recovered.
    [Show full text]
  • Application to Grape Powdery Mildew (Erysiphe Necator) in Vineyards
    agronomy Article Disease Risk Forecasting with Bayesian Learning Networks: Application to Grape Powdery Mildew (Erysiphe necator) in Vineyards Weixun Lu 1 , Nathaniel K. Newlands 2,∗ , Odile Carisse 3, David E. Atkinson 1 and Alex J. Cannon 4 1 Department of Geography, University of Victoria, David Turpin Building, 3800 Finnerty Road, Victoria, BC V9P 5C2, Canada; [email protected] (W.L.); [email protected] (D.E.A.) 2 Science and Technology, Agriculture and Agri-Food Canada, Summerland Research and Development Centre, 4200 Highway 97 S, P.O. Box 5000, Summerland, BC V0H 1Z0, Canada 3 Science and Technology, Agriculture and Agri-Food Canada, Saint-Jean-sur-Richelieu Research and Development Centre, 430 Gouin Boulevard, Saint-Jean-sur-Richelieu, QC J3B 3E6, Canada; [email protected] 4 Climate Research Division, Environment and Climate Change Canada, 3800 Finnerty Road, Victoria, BC V8P 5C2, Canada; [email protected] * Correspondence: [email protected] Received: 14 March 2020; Accepted: 17 April 2020; Published: 28 April 2020 Abstract: Powdery mildew (Erysiphe necator) is a fungal disease causing significant loss of grape yield in commercial vineyards. The rate of development of this disease varies annually and is driven by complex interactions between the pathogen, its host, and environmental conditions. The long term impacts of weather and climate variability on disease development is not well understood, making the development of efficient and durable strategies for disease management challenging, especially under northern conditions. We present a probabilistic, Bayesian learning network model to explore the complex causal interactions between environment, pathogen, and host for three different susceptible northern grape cultivars in Quebec, Canada.
    [Show full text]
  • Citrus Blight and Other Diseases of Recalcitrant Etiology
    P1: FRK August 1, 2000 18:44 Annual Reviews AR107-09 Annu. Rev. Phytopathol. 2000. 38:181–205 Copyright c 2000 by Annual Reviews. All rights reserved CITRUS BLIGHT AND OTHER DISEASES OF RECALCITRANT ETIOLOGY KS Derrick and LW Timmer University of Florida, Institute of Food and Agricultural Sciences, Citrus Research and Education Center, Lake Alfred, Florida 33850-2299; e-mail: [email protected]fl.edu, [email protected]fl.edu Key Words citrus psorosis, citrus variegated chlorosis, lettuce big vein, peach tree short life, replant diseases ■ Abstract Several economically important diseases of unknown or recently de- termined cause are reviewed. Citrus blight (CB), first described over 100 years ago, was shown in 1984 to be transmitted by root-graft inoculations; the cause remains unknown and is controversial. Based on graft transmission, it is considered to be an infectious agent by some; others suggest that the cause of CB is abiotic. Citrus varie- gated chlorosis, although probably long present in Argentina, where it was considered to be a variant of CB, was identified as a specific disease and shown to be caused by a strain of Xylella fastidiosa after if reached epidemic levels in Brazil in 1987. Citrus psorosis, described in 1933 as the first virus disease of citrus, is perhaps one of the last to be characterized. In 1988, it was shown to be caused by a very unusual virus. The cause of lettuce big vein appears to be a viruslike agent that is transmitted by a soilborne fungus. Double-stranded RNAs were associated with the disease, suggesting it may be caused by an unidentified RNA virus.
    [Show full text]
  • Ontogenic Resistance in Grape Leaves to Powdery Mildew and Models Of
    Ontogenic resistance in grape leaves to powdery mildew and models of shoot development (original title: Response of grapevine canopies to chemical elicitors that induce disease resistance) FINAL REPORT to GRAPE AND WINE RESEARCH & DEVELOPMENT CORPORATION Project Number: UT 04/01 Principal Investigator: Katherine J. Evans Research Organisation: University of Tasmania Date: 31 December, 2008. Australian Grape and Wine Research and Development Corporation Project Number: UT 04/01 Project Title: Ontogenic resistance in grape leaves to powdery mildew and models of shoot development Original title: Response of grapevine canopies to chemical elicitors that induce disease resistance. Report Date: December 31, 2008. Authors: Katherine J. Evans 1 (Senior Research Fellow), Angela M. Smith 1 (PhD student) and Stephen J. Wilson 2 (Lecturer, School of Agricultural Science) Tasmanian Institute of Agricultural Research University of Tasmania 113 St Johns Avenue, New Town TAS 7008 2Private Bag 54, Hobart TAS 7001 Australia email: [email protected] Phone: 61-3-6233 6878 Fax: 61-3-6233 6145 Acknowledgements This report presents preliminary outcomes of the PhD project of Ms Angela Smith, prior to thesis submission for examination. Ms Smith received an Australian Postgraduate Award from the University of Tasmania, with further support from the GWRDC. K.J. Evans was the first-named PhD supervisor, with co-supervision provided by Dr Stephen Wilson of the School of Agricultural Science, University of Tasmania (UTAS). Special thanks to Dr Phil Brown, UTAS, for advice on radiolabelling and Dr Ross Corkrey, UTAS, for developing the Bayesian models and general statistical advice. Sincere thanks also to Mr Paul Schupp and others for technical assistance.
    [Show full text]
  • Dual RNA Sequencing of Vitis Vinifera During Lasiodiplodia Theobromae Infection Unveils Host–Pathogen Interactions
    International Journal of Molecular Sciences Article Dual RNA Sequencing of Vitis vinifera during Lasiodiplodia theobromae Infection Unveils Host–Pathogen Interactions Micael F. M. Gonçalves 1 , Rui B. Nunes 1, Laurentijn Tilleman 2 , Yves Van de Peer 3,4,5 , Dieter Deforce 2, Filip Van Nieuwerburgh 2, Ana C. Esteves 6 and Artur Alves 1,* 1 Department of Biology, CESAM, University of Aveiro, 3810-193 Aveiro, Portugal; [email protected] (M.F.M.G.); [email protected] (R.B.N.) 2 Laboratory of Pharmaceutical Biotechnology, Campus Heymans, Ottergemsesteenweg 460, B-9000 Ghent, Belgium; [email protected] (L.T.); [email protected] (D.D.); [email protected] (F.V.N.) 3 Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium; [email protected] 4 Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium 5 Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria 0028, South Africa 6 Faculty of Dental Medicine, Center for Interdisciplinary Research in Health (CIIS), Universidade Católica Portuguesa, Estrada da Circunvalação, 3504-505 Viseu, Portugal; [email protected] * Correspondence: [email protected]; Tel.: +351-234-370-766 Received: 28 October 2019; Accepted: 29 November 2019; Published: 3 December 2019 Abstract: Lasiodiplodia theobromae is one of the most aggressive agents of the grapevine trunk disease Botryosphaeria dieback. Through a dual RNA-sequencing approach, this study aimed to give a broader perspective on the infection strategy deployed by L. theobromae, while understanding grapevine response. Approximately 0.05% and 90% of the reads were mapped to the genomes of L.
    [Show full text]
  • Epidemiology of Grape Powdery Mildew, Uncinula Necator, in the Willamette Valley
    An Abstract of the Thesis of Tyrone W. Hall for the degree of Master of Science in Botany and Plant Pathology presented on February 07,2000. Title: Epidemiology of Grape Powdery Mildew, Uncinula necator, in the Willamette Valley. Redacted for Privacy Abstract approved: W Iter F. Mahaffee An important disease of Vitis vinifera production in Oregon and all other commercial growing regions is powdery mildew of grape, caused by the obligate fungal pathogen Unci nula necator (Schwein.) Burril. Grape production can be characterized as a long-term investment in the establishment and maintenance of the vineyard. Establishment times have been reduced with the use of plastic vine shelters, but powdery mildew disease pressure within vine shelters had been an unaddressed issue. Control of the pathogen requires frequent spray applications and costly cultural management of the grape canopy. Industry interest in forecasting programs have shown promise in regulating spray applications to times when they are most effective, or needed. The timing of when to begin spray programs is believed to be a point of weakness in the forecasting programs currently available for grape powdery mildew. The influence of vine shelter use on the development of powdery mildew was investigated in the field during the 1998 and 1999 growing season. Industry standard installations of various brands of vine shelters were tested against modified installations for both incidence and severity of Uncinula necator infection. The industry standard installation of76 ern high tubes hilled with 8 ern of soil at the bottom to prevent airflow, were effective in reducing the incidence of powdery mildew in both field seasons.
    [Show full text]
  • Genome and Transcriptome Analysis of the Latent Pathogen Lasiodiplodia Theobromae, an Emerging Threat to the Cacao Industry
    Genome Genome and transcriptome analysis of the latent pathogen Lasiodiplodia theobromae, an emerging threat to the cacao industry Journal: Genome Manuscript ID gen-2019-0112.R1 Manuscript Type: Article Date Submitted by the 05-Sep-2019 Author: Complete List of Authors: Ali, Shahin; Sustainable Perennial Crops Laboratory, United States Department of Agriculture Asman, Asman; Hasanuddin University, Department of Viticulture & Enology Draft Shao, Jonathan; USDA-ARS Northeast Area Balidion, Johnny; University of the Philippines Los Banos Strem, Mary; Sustainable Perennial Crops Laboratory, United States Department of Agriculture Puig, Alina; USDA/ARS Miami, Subtropical Horticultural Research Station Meinhardt, Lyndel; Sustainable Perennial Crops Laboratory, United States Department of Agriculture Bailey, Bryan; Sustainable Perennial Crops Laboratory, United States Department of Agriculture Keyword: Cocoa, Lasiodiplodia, genome, transcriptome, effectors Is the invited manuscript for consideration in a Special Not applicable (regular submission) Issue? : https://mc06.manuscriptcentral.com/genome-pubs Page 1 of 46 Genome 1 Genome and transcriptome analysis of the latent pathogen Lasiodiplodia 2 theobromae, an emerging threat to the cacao industry 3 4 Shahin S. Ali1,2, Asman Asman3, Jonathan Shao4, Johnny F. Balidion5, Mary D. Strem1, Alina S. 5 Puig6, Lyndel W. Meinhardt1 and Bryan A. Bailey1* 6 7 1Sustainable Perennial Crops Laboratory, USDA/ARS, Beltsville Agricultural Research Center-West, 8 Beltsville, MD 20705, USA. 9 2Department of Viticulture & Enology, University of California, Davis, CA 95616 10 3Department of Plant Pests and Diseases, Hasanuddin University, South Sulawesi, Indonesia. 11 4USDA/ARS, Northeast Area, Beltsville, MDDraft 20705, USA. 12 5 Institute of Weed Science, Entomology and Plant Pathology, University of the Philippines, Los Banos, 13 Laguna 4031, Philippines.
    [Show full text]
  • Studies on the Storage Rot of Sweet Potato
    STUDIES ON THE STORAGE ROT OF SWEET POTATO (IPOMOEA BATATAS L & LAM) BY BOTRYODIPLODIA THEOBROMAE PAT. AND OTHER FUNGI By Anthony Elue Arinze B.Sc., M.Sc. (Lagos) a A thesis submitted in part fulfilment of it) the requirements for the Degree of Doctor of Philosophy of the University of London. Department of Botany and Plant Technology Imperial College of Science and Technology Field Station Silwood Park Ascot Berkshire U.K. AUGUST, 1978 - 2 - ABSTRACT The storage rot of sweet potato (s.p.) (Ipomoea batatas) tuberous roots by Botryodiplodia theobromae (B.t.), Botrytis cinerea (B.c.) and Cladosporium cucumerinum (C.c.) was studied. The tuber was susceptible to rot by B. theobromae but was coloni,ed to a limited extent by B. cinerea and C. cucumerinum. The role of pectic enzymes in the successful rotting of s.p. by B.t. was investigated. B.t. produced four PG isoenzymes in vitro one of which was recovered from rotted sweet potato tissue. The properties of these isoenzymes were studied. The possible interaction between the host's metabolites (phenols and oxidative • enzymes) and the pectic enzymes of B.t. was discussed in relation to the successful rotting of the tuber by the fungus. Comparatively little pectic enzyme (PG) was recovered from tissues inoculated with B.c. and no pectic enzyme was found in tissues inoculated with C.c. Low temperature treatment (0-7°C) of the tuber induced chilling injury rendering the tissues more susceptible to rot by the fungi. The accumulation of antifungal compounds by s.p. inoculated with B.t., B.c.
    [Show full text]
  • Disease Updates on Muscadines (Bill Cline, NCSU) (PDF)
    Muscadine Disease Update 28 August 2019 Bill Cline and Benny Bloodworth Entomology and Plant Pathology Horticultural Crops Research Station Castle Hayne NC Pathogens spread by microscopic propagules (spores, bacteria, virus particles) that are too small to see Image below: Hundreds of bitter rot spores Image below: Masses of black spores compared in size with a single human hair produced on the surface of an infected grape Human hair Diseased Spores Healthy Bitter rot caused by the fungus Greeneria uvicola Biotic or Abiotic? Using Signs and Symptoms as a Guide What to look for at this time of year (late August, early September, beginning harvest, fungicide sprays mostly finished for the year) SIGNS are the visible parts of the pathogenic organism – in this example, the pathogen is a fungus producing signs (mold and spores) on a stored orange SYMPTOM -- Spray burn -- front vs back of the same cluster of blueberries SYMPTOM – abiotic injury -- hail damage on strawberry and blueberry Hail damage to green fruit 2,4-D herbicide injury 2,4-D on blueberry (and nearby oak) Ripe Rot • Fungus (Colletotrichum sp.) • Spreads by splashing rain, insects • Clustered in “hot spots” along the cordon • Brown-colored rot with pink to orange spore masses Powdery Mildew • Fungus (Uncinula necator) • Appears as faint white “powder” on young fruit • Causes brown russeting on surface • Affected fruit cannot ripen normally; may crack Spray Timing – much simpler for muscadine (compared to Vinifera) • Mid-May (Before disease is visible) • Shoots 6-10 inches in length
    [Show full text]
  • SR-112 Science of Hemp: Production and Pest Management
    University of Kentucky College of Agriculture, Food and Environment Agricultural Experiment Station SR-112 Science of Hemp: Production and Pest Management Science of Hemp: Production and Pest Management October 10 –11, 2019 Agricultural Kentucky Tobacco Research and Development Center | Veterinary Diagnostic Laboratory | Division of Regulatory Services | Research and Education Center Experiment Station Robinson Forest | Robinson Center for Appalachian Resource Sustainability | University of Kentucky Superfund Research Center | Equine Programs emp (Cannabis sativa with <0.3% THC content) is grown for fiber, grain, and cannabinoid extraction in Asia, Europe, and the Americas. Until recently, HCannabis sativa has been classified as a Schedule 1 controlled substance in the US. The Agricultural Act of 2014 (Farm Bill) allowed for reintroduction of industrial hemp under a pilot research program. Acreage increases and addition of state legislation resulted in over 78,000 acres of hemp grown in 23 states by the end of 2018. Hemp became a legal commodity under the 2018 Farm Bill, and by the end of 2019, over 500,000 licensed acres were documented across 45 states. Canada re-introduced the crop in 1998, and in 2018, almost 78,000 acres of hemp were licensed and planted. With this increase in acreage and the lack of modern scientific data, university and government agricultural specialists began to work on various components of production and a range of realized challenges. This new information, however, had either not been shared or was not readily accessible to the scientific community, especially early results and nonpublished data. The first annual meeting of the Science of Hemp: Production and Pest Management was held on October 10-11, 2019 at the University of Kentucky in Lexington, KY.
    [Show full text]
  • Grapevine Trunk Diseases in German Viticulture. III. Biodiversity and Spatial Distribution of Fungal Pathogens in Rootstock Moth
    Vitis 58, 141–149 (2019) DOI: 10.5073/vitis.2019.58.141-149 Grapevine trunk diseases in German viticulture. III. Biodiversity and spatial distribution of fungal pathogens in rootstock mother plants and possible relation to leaf symptoms M. FISCHER Julius Kühn-Institut (JKI), Federal Research Centre for Cultivated Plants, Plant Protection in Fruit Crops and Viticulture, Siebeldingen, Germany Summary Introduction Three rootstock mother blocks, planted with cul- Grapevine trunk diseases (GTDs) affecting young tivars SO4 (planted 2004), 125AA (2005) and 5BB vines and nursery processes include the Esca disease com- (2005), and located in southwestern Germany were plex (for definition of esca complex diseases see, among examined for the existence of grapevine trunk disease others, SURICO 2001, 2009), black-foot disease (AGUSTÍ-BRI- (GTD) pathogens and related internal and external SACH and ARMENGOL 2013, AGUSTÍ-BRISACH et al. 2013) and symptoms between 2011 and 2017. Frequency of leaf Botryosphaeria dieback (reviewed by BERTSCH et al. 2012). symptoms ranged from 0.2 % in six-year old blocks Eutypa dieback, due to several species of diatrypaceous to appr. 1.5 % in 12-year-old blocks. While the typical fungi, mostly Eutypa lata (Elata), is apparent in older vine- "tiger stripe pattern" was less common, the majority yards only (LECOMTE et al. 2000, ROLSHAUSEN et al. 2014). of affected leaves was characterized by irregularly ar- Between 25 and 50 millions of graftlings are annu- ranged necrotic spots spread over the leaf surface. Ir- ally produced by German nurseries (Verband Deutscher respective of leaf symptoms, in cross sections of 9-12 Rebenpflanzguterzeuger, pers. comm.).
    [Show full text]
  • Proceedings 32Nd Meeting
    Proceedings 32nd Meeting 25. - 27.03.2019, Bonn, Germany Production of table grapes in Brazil Mônica Ishikawa, AMV — Serviços e Consultoria Ltda / ABRAFRUTAS © BLE Imprint Federal Office for Agriculture and Food Bundesanstalt für Landwirtschaft und Ernährung (BLE) President: Dr. Hanns-Christoph Eiden Deichmanns Aue 29 53179 Bonn, Germany Telephone: ++49 (0)228 6845 - 0 Fax: ++49 (0)30 1810 6845 - 3444 E-mail: [email protected] Editing Dr. Ulrike Bickelmann, BLE Telephone: ++49 (0)228 6845 - 3357 E-mail: [email protected] Date of issue November 2019 © BLE 1 Production of Table Grapes in Brazil Mônica Ishikawa, AMV – SERVIÇOS E CONSULTORIA LTDA Brazil is the number 3 of world fruit producers indicator. The irrigation water used on the and number 16 of fruit exporters. The fields is provided mainly by the San Francisco fruticulture covers 2.5 million hectars in Brazil River. Heavy irrigation investments have and provides 5 million of employments. The been developed by the government. Due to gross value of fruit production in 2017 is 33.3 the quality of the water, there is no danger of billion US $. The main destination of Brazilian causing the salinity of the soil. fruits is the market of the European Union (67 % by volume). However, the percentage The annual average temperature of 30 °C and of exported fruits it only 2.5 % and the rest is the relative humidity of about 40 %, alongside destined for the domestic market. with the high luminosity enable, technically, the fruit production throughout the year, In 2016, table grapes were ranking number offering all times, healthy products and with 10 by global production volume.
    [Show full text]